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A port of the Free Lossless Audio Codec (FLAC) decoder to Java and a FLAC encoder implemented in Java.

There is a newer version: 1.4.1

/*
 * Copyright (C) 2010  Preston Lacey http://javaflacencoder.sourceforge.net/
 * All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package net.sourceforge.javaflacencoder;
import java.util.concurrent.locks.ReentrantLock;

/**
 * The FrameThread class provides threading support for a Frame object, allowing
 * multi-threaded encodings of FLAC frames. It's job is to repeatedly get a
 * BlockEncodeRequest from a BlockThreadManager, and encode it.
 *
 * @author Preston Lacey
 */
public class FrameThread implements Runnable {
  Frame frame = null;
  ReentrantLock runLock = null;
  BlockThreadManager manager = null;
  /**
   * Constructor. Private to prevent it's use, as a Frame must be provided for
   * this FrameThread to be of any use.
   */
  private FrameThread() {}

  /**
   * Constructor. Sets the Frame object that this FrameThread will use for
   * encodings.
   *
   * @param f Frame object to use for encoding.
   * @param manager BlockThreadManager to use as the BlockEncodeRequest source
   * and destination.
   */
  public FrameThread(Frame f, BlockThreadManager manager) {
    super();
    if(f == null)
      System.err.println("Frame is null. Error.");
    frame = f;
    runLock = new ReentrantLock();
    this.manager = manager;
  }

  /**
   * Run method. This FrameThread will get a BlockEncodeRequest from the
   * BlockThreadManager, encode the block, return it to the manager, then
   * repeat. If no BlockEncodeRequest is available, or if it recieves a
   * request with the "frameNumber" field set to a negative value, it will
   * break the loop and end, notifying the manager it has ended.
   *
   */
  public void run() {
    boolean process = true;
    synchronized(this) {
      BlockEncodeRequest ber = manager.getWaitingRequest();
      if(ber != null && ber.frameNumber < 0)
         ber = null;
      while(ber != null && process) {
        if(ber.frameNumber < 0) {
          process = false;
        }
        else {//get available BlockEncodeRequest from manager
          ber.encodedSamples = frame.encodeSamples(ber.samples, ber.count,
          ber.start, ber.skip, ber.result, ber.frameNumber);
          ber.valid = true;
          manager.returnFinishedRequest(ber);
          ber = manager.getWaitingRequest();
        }
      }
      manager.notifyFrameThreadExit(this);
    }
  }
}